As indispensable drilling-related equipment used in construction of geotechnical engineering such as geological exploration and control, exploitation of oil and gas wells and drilling for special purposes, mud pumps are used for conveying, to the drill pipe during the drilling, media such as mud and water which function as cooling and washing the drill pipe and the soil.
At present, most of the existing mud pumps operate in a conventional way in which the reciprocating motion is driven by a mechanical crank-link mechanism. Usually, the reduction of speed is realized by belt drive by using a diesel engine or motor or realized by a gear reducer; and then the piston rod and the plunger of the mud pump head are driven by the crank-link mechanism and the guide slider to do reciprocating motion. In this way, the suction and discharge functions of the mud pump head are achieved. With regard to a conventional mud pump, due to the use of the crank-link mechanism, the running speed of the plunger of the mud pump head changes approximately in a sinusoidal fashion. As a result, the instantaneous flow and pressure of the discharged liquid also change approximately in a sinusoidal fashion, with large fluctuation. In order to decrease the fluctuation in flow and pressure inside the discharge manifold of the mud pump head, as a conventional technical solution, a pulsation damper is provided at the discharge outlet of the mud pump head. However, this increases the weight of the equipment and the difficulty of maintenance.
To meet the growing demands for mud pumps in the construction of geotechnical engineering, the development of a mud pump with novel structure and small fluctuation to replace the conventional mud pump which is driven by a crank-link mechanism has become an inevitable trend.